/*
 * Copyright (C) 2009 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.io;

import java.io.IOException;

/**
 * A callback interface to process bytes from a stream.
 * 
 * <p>
 * {@link #processBytes} will be called for each line that is read, and should
 * return {@code false} when you want to stop processing.
 * 
 * @author Chris Nokleberg
 * @since 2009.09.15 <b>tentative</b>
 */
public interface ByteProcessor<T> {
    /**
     * This method will be called for each chunk of bytes in an input stream.
     * The implementation should process the bytes from {@code buf[off]} through
     * {@code buf[off + len - 1]} (inclusive).
     * 
     * @param buf
     *            the byte array containing the data to process
     * @param off
     *            the initial offset into the array
     * @param len
     *            the length of data to be processed
     * @return true to continue processing, false to stop
     */
    boolean processBytes(byte[] buf, int off, int len) throws IOException;

    /** Return the result of processing all the bytes. */
    T getResult();
}
